Striped seabream, Lithognathus mormyrus L. (n=731) caught off the Canary Islands from January 1999 to June 2000 were studied. Fish ranged in size from 113 to 372 mm total length, weighing from 21.1 to 748.2 g total weight. Weight increased allometrically with size (b=2.9071). Fish age was 0–10‐years‐old. Growth was relatively slow (k=0.88 years−1), with females growing at a slightly faster rate than males. The species displayed protandric hermaphroditism. Male : female ratio was unbalanced in favour of males (1 : 0.85). Males predominated in smaller sizes, females in larger sizes, and intersexual individuals were in intermediate sizes. The reproductive season extended from June to December, with a peak in spawning activity in August–September. Males reached maturity at 207 mm (2 years) and females at 246 mm (3 years). The real value of instantaneous rate of natural mortality was between 0.30 and 0.45 years−1.

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Axillary seabream Pagellus acarne "Risso 0715# caught o} the Canary Islands from January 0880 to December 0883 were studied[ The length range of the catches was between 00 and 20 cm\ with a modal distribution between 06 and 10 cm[ The overall ratio of males to females was 0]0[63[ Males were observed up to a length of 13 cm[ Hermaphrodites were re! corded at lengths between 04 and 12 cm[ The species was char! acterized by protandric hermaphroditism[ The reproductive season extended from October to March\ with a peak in spawn! ing activity in DecemberÐJanuary[ The size at sexual maturity was 04[7 cm total length "1 years old# for males and 08[3 cm total length "2 years old# for females[ The total lengthÐtotal weight relationship for the entire population is described by the parameters a 9[9957\ and b 2[1390[ Otolith age readings showed that the population exploited consisted of 09 age groups "0Ð09 years#\ including a very high proportion of individuals between 0 and 3 years old[ The von Bertalan}y growth par! ameters for all individuals were L 21[87 cm\ k 9[11 years −0 \ and t 9 −9[76 years[ Males grew comparatively slower than females[ The instantaneous rates of mortality for all _sh were Z 9[85 years −0 \ M 9[29 years −0 \ and F 9[55 years −0 [ The exploitation ratio and the length at _rst capture were\ respectively\ E 9[58 and LC 49 05[0 cm[ The stock is overexploited\ therefore measures such as closed seasons or changes in _shing patterns would be desirable to safeguard the spawning stock and recruits[

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SummaryThe biology of the Canary Islands annular seabream Diplodus annularis (Linnacus 1758) was studied from samples collected between January and December 1998. Fish ranged from 82 to 209 mm total length in size and from 8.7 to 137 1 g in weight.The mean length showed an increase with increasing water depth. Males showed a negative allometric growth and females isometric growth The species was characterized by protandric hermaphroditism. The overall sex ratio was unbalanced in favour of males (1 : 0.79). The reproductive season extended from January to May, with a peak in spawning activity in March-April. Males reached maturity at a smaller length (103 mm, 1-year-old) than females (128 mm, 2-year-old). Fish aged M years were found. The von Bertalanffy growth parameters for al1 individuals were: L, = 247.9 mm, k = 0.268 years-l. and t0 =-O.879 years.

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Summary Moroccan white seabream Diplodus sargus cadenati (n = 603) were caught off the Canary Islands from April 2000 to March 2001. Total length ranged from 46 to 404 mm. The subspecies was characterized as being dygynous with partial protandry. Overall ratio of males to females was 1 : 2.9. The reproductive season extended from December to May, with a peak in spawning activity in January–February. Fifty per cent maturity was reached at 201 mm total length in males and 216 mm in females. The length–weight relationship for all individuals was described by the following parameters: a = 0.000023, and b = 2.96, when length is given in millimeters and weight in grams. Fish of 0–12 years in age were found. The von Bertalanffy growth parameters for the entire population were: L∞ = 467 mm, k = 0.143 year−1 and t0 = −2.14 year. Growth parameters differed between males and females. For all fish, instantaneous rates of mortality were Z = 0.68 year−1, M = 0.31 ± 0.6 year−1 and F = 0.37 ± 0.6 year−1; the exploitation ratio was E = 0.54 ± 0.9. Length at first capture for all individuals was 173 mm. The stock exploited above is an assumed optimum.